Wood stains



surface with a filler.

WGOD STANS Harry A. Toulmin, .lra, Dayton, Ohio, assignor to CharleloidCorporation, Dayton, Ulric, a corporation of Delaware No Drawing.Application September 27, 1955, Serial No. 537,065

2 Claims. (Cl. 106-434) This invention relates to stains, especiallystains for use on wood and to compositions for use in staining woodarticles and the like, as well as methods for staining such articles.

This application is a continuation-in-part of application Serial No.362,655, filed June 18, 1953, now aban- 9 doned, the latter being adivision of my application Serial No. 277,919, filed March 21, 1952, nowabandoned.

The art of wood staining in the past has made use of dyes which weredissolved or dispersed solvents and the like diluents so as to make thesame applicable for apply- 0 'ing as a spray, dip, or by brush. Thewater-soluble stains "The grain raising effect of such water-solublestains also quakes it necessary to apply a sealer coating such asshellac to the stained wood in order to stiffen the fibers of the woodso that the surface can be uniformly sanded. When an open-grain wood isused, it is necessary after the sanding operation to apply a filler tothe surface over which is then applied a varnish, lacquer or otherdesired coatmg.

The non-aqueous stains, for example, oil stains and spirit stains, andwhich generally consist of an aniline dye or aniline dry base dissolvedin an organic solvent such as a hydrocarbon or alcohol, have beenextensively used and have certain advantages over water stains. Theyalso have certain undesirable features. The use of hydro carbons, suchas benzol, toluol or other petroleum distillates that are highlyvolatile when applied to the surface to be treated tends to leave thepores of the wood unimpregnated with the dye. They are also dangerous inmass application in a furniture factory. Where such composition isapplied to a wood surface having open grain, it has been the practiceafter drying to treat the Again, before applying the finish coating ofvarnish or lacquer, there must be applied a coating of shellac orsimilar functioning coating over either the stain or the tiller in orderto prevent bleeding. This application of shellac or the like isnecessary, otherwise the solvents of the varnish or lacquer willpenetrate into the stain and cause the color to bleed into the finishcoat. The use of hydrocarbon solvents also is undesirable from thestandpoint of fire hazard and the effect the volatile solvent may haveon the operator applying the stain.

The spirit stains are not as useful as the water stains because they aresubject to the disadvantage that such stains do not penetrate into thewood stains and they further lack permanency of color and tend to fadein use, similar as the oil type stains. Spirit stains are also subjectto the bleeding effect, and in many instances, also produce theundesirable grain raising upon application to the Wood surface,

2,813,801 Patented Nov; 19, 1957 In accordance with the presentinvention, I have discovered that by combining citrus flavanonederivatives, for example, hesperetin, naringenin and eriodictyol as maybe obtained from citrus pulp and citrus waste, with aniline or alkyl oraryl substituted aniline bases, as by coupling of the flavanone todiazotized aniline or amino compounds, and dispersing the resultant dyein water solution, an excellent wood staining composition is provided.The socalled citrns-azo dye can be readily fixed in the cellulose poresof the wood since it has an affinity for cellulose and is compatiblewith it. The coupled fiavanone amino-dye reaction product is capable ofremaining in aqueous suspension thereby forming a coloring materialcompatible with the cellulose from which it is derived so that the dyesolution will carry into the wood. I

It may be applied as a hot or cold aqueous solution to the wood. A hot,aqueous solution of such citrus-azo dyes, as made from these citrusflavanones and obtained from citrus waste, being derived from acellulose source, forms a staining solution which is completelycompatible with wood and cellulose products. Application of the dyesolution to wood results in a highly desirable stain effect, the dyeforming a dispersion of uniform character and one which deeplypenetrates into the pores of the Wood without raising the grain.

The aqueous staining solutions of this invention which comprise theaforementioned citrus-azo dyes are preferably applied as a hot aqueoussolution, although they are also effective as a wood stain when appliedas a cold solution. Hot aqueous solutions of such dyes when appliedpenetrate into the Wood and the solvent evaporates before the grain ofthe wood is caused to raise. Upon cooling, the dye is set in the woodand forms a smooth uniformly stained wood surface which needs no sandingor other treatment to produce a desirablejsurface upon which may beapplied a finish coating of varnish or lacquer.

In accordance with the invention, a Wood staining composition isprovided which is very inexpensive and easy to manufacture, and whereinthe use of expensive organic diluents and solvents and the like, withtheir attendant disadvantages may be entirely eliminated.

The formula of naringenin (as shown by Karrers Organic Chemistry,1950-edition) is as follows:

The formula of hesperetin is given as follows:

CO H5 Eriodictyol, which is a tetrahydroxy flavanone is as follows:

O OH

- The combinationcitrus-azo dyes which are utilized in forming the woodstaining composition of this invention are exemplified by the followingformulae and which are illustrated graphically below:

Coupling aniline with naringenin, e. g. as recovered fromgrapefruitwaste, results in the production of an azo dye having theprobable structural formula:

C O HO Substituting eriodictyol for naringenin the formula wouldEmploying hesperetin as recovered from orrange waste, and coupling thiscompound with aniline, there results the production of an azo dye havingthe probable structural formula:

0 on E0 Err-Q0011 o o no Example I (1) To a solution comprising 0.1 moleof aniline in water is added 0.25 mol of hydrochloric acid. The mixtureis diluted 50% by volume with water and cooled to a temperature of about10 C.

While maintaining the temperature of the mixture at about 10 C. there isadded slowly over a period of about 10 to 15 minutes a 0.1 mol aqueoussolution of sodium nitrite. This mixture is then stirred for one-halfhour while maintaining the temperature at about 10 C. This results inthe formation of the diazonium salt CsHsNzCl.

(2) To effect the coupling action with the diazonium salt 1), an aqueoussolution containing 0.1 mol of hesperetin dissolved in 0.1 mol of sodiumhydroxide is employed. The resultant solution is diluted 50% by volumewith water and cooled to between 5 and C. Thereafter, the diazo of (1)is stirred into the mixture over a minute period while maintaining thetemperature at about l0-l5 C. and the pH of the solution above 9. Afterstirring the mixture for half an hour more, the dyestufi is isolated byadjusting the pH of the solution to neutral with dilute hydrochloric(0.1 N) and adding a salt, i. e., sodium chloride or sodium sulfate,until the dye precipitates from the solution. Thereafter, the mixture isfiltered to recover the diazoaminohesperetin dyestufi.

Example 11 A wood stain is prepared by making up a 5% aqueous solution(5 gms. dyestuff/ gms. water) of the diazoaminohesperetin. The resultantstaining solution may be applied to wood by spraying, brushing ordipping and allowed to dry. Force air drying at 250 F. may be used whereseparate articles of wood or pieces are to be stained.

A combination stain and filler may be formulated for use as a wood stainand filler composition as follows:

Example III To a 10% aqueous solution of the dyestufi of Example I isintroduced 8% by weight of asbestine (300 mesh). The asbestine ispreferably introduced as an aqueous paste containing 50% by weightasbestine, the filler being suitably ground or dispersed therein bymeans of a pebble mill or roller mill. To assist the dispersion of thefiller particles and improve brushing properties of the stainfillercomposition 1% by weight of polyethylene glycol monolaurate (based uponthe liquid vehicle of the paste) is introduced. The ethylene oxide ofthe glycol laurate is polymerized with stannic chloride to a molecularweight of about 4500 to 4900.

In place of asbestine, there may be substituted for all or a portionthereof other suitable fillers, e. g. wood flour, infusorial earth,talc, kaolin and the like, the proportionate amount added being variedto produce a product which can be applied by brushing, dipping, orspraying.

Example IV Aniline diazotized is coupled with naringenin as in ExampleI, by reacting a solution of naringenin dissolved in sodium hydroxide at15-25 C. with the mixture being kept above pH 9. After heating to 25 C.and stirring the mixture for half an hour, the dyestutf is isolated byadjusting the pH of the solution to neutral with dilute hydrochloricacid, then sodium chloride is added until the dye precipitates from thesolution. The solution is then filtered to recover adiazoaminonaringenin dyestufi.

Example V A wood stain is prepared by providing an aqueous solution ofthe dyestutl of Example IV in water to form a 5% sodlution. The stainsolution may be applied by brushing or spraying woods to stain the same.

Example VI A 50-50 mixture of naringenin and hesperetin is coupled withdiazotized aniline as in Example I to produce mixed naringeninhesperetin diazoaminoflavanone dyestutl.

Example VII A wood stain is prepared by dispersing the resultantdyestufl? of Example VI in water to form a 10% solution (10 gms.dyestutf/ 100 gms. water) which may be sprayed or brushed onto wood andair dried to produce a stained wood.

Example VIII Example IV is repeated using eriodictyol in place of narngemn as the coupling component to produce a diazoaminoeriodictyoldyestufi.

Example IX A wood stain is prepared by making up an aqueous solution ofthe dyestufi of Example VIII. A 6% solution (6 gms. dyestuti in 100 gms.water) provides a staining composition. Where a filler is desired, 5% byweight of the solution may comprise wood flour. Talc especially fibroustype may also be used as the filler alone or mixed 50-50% by weight withwood flour.

In accordance with the present invention, it is possible for the firsttime to utilize such water soluble azo dyes made by coupling a flavanonederivative, such as naringenin, eriodictyol or hesperetin with anilineor other suitable diazotizing amino compound to form a watersoluble dyewhich yields, upon dispersion in an aqueous vehicle, a wood stain whichis substantially fast to light, and exhibits non-fading, non-grainraising properties. A wood stain also is provided, which, when properlycompounded and applied as described, does not bleed through lacquer orvarnish top finishing coats. Thus, the use of intermediate sealing coatsis not necessary. Where desired, of course, intermediate sealing coatsof suitable type may be employed.

It will be understood that while there have been described hereinspecific embodiments of this invention, it is not intended thereby tohave it limited to or circumscribed by the specific details given inview of the fact that this invention is susceptible to variousmodifications and changes which come within the spirit of thisdisclosure and the scope of the appended claims.

What is claimed is:

1. A combination wood staining and filling composition comprising an azodye in which the coupling component is chosen from the group consistingof naringenin, hesperetin and eriodictyol, and containing inert organicfiller and water suflicient to form at least a 5% solution, said fillercomprising an aqueous paste and wherein the filler is selected from thegroup consisting of asbestine, fibrous talc and wood flour, and saidcomposition containing about 1% by weight of polyethylene glycolmonolaurate based upon the liquid vehicle of the paste.

2. A combination wood staining and filling composition comprising an azodye in which the coupling component is chosen from the group consistingof naringenin, hesperetin and eriodictyol, said composition comprising a10% aqueous solution of said dye and 8% by weight of asbestine fillerconsisting of aqueous paste containing 50% by weight of asbestine, andsaid composition containing about 1% by weight of polyethylene glycolmonolaurate based upon the liquid vehicle of the paste.

References Cited in the file of this patent UNITED STATES PATENTS

1. A COMBINATION WOOD STAINING AND FILLINNG COMPOSITION COMPRISING ANAZO DYE IN WHICH THE COUPLING COMPO-NENT IS CHOSEN FROM THE GROUPCONSISTING OF NARINGENIN, HESPERETIN AND ERIODICTYOL, AND CONTAININGINERT ORGANIC FILLER AND WATER SUFFICIENT TO FORM AT LEAST A 5%SOLUTION, SAID FILLER COMPRISING AN AQUEOUS PASTE AND WHEREIN THE FILLERIS SELECTED FROM THE GROUP CONSISSTING OF ASBESTINE, FIBROUS TALC ANDWOOD FLOUR, AND SAID COMPOSITION CONTAINING ABOUT 1% BY WEIGHT OFPOLYETHYLENE GLYCOL MONOLAURATE BASED UPON THE LIQUID VEHICLE OF THEPASTE.